Take note of the additional protection offered by the inverter ... @ 0.24 including:

Lightning protection built in.

Anti islanding (common on most inverters)

Insulation resistance detection.

Residual current protection (as we refer to as earth leakage protection) 

Output short circuit protection.

Output over voltage protection.

Arc protection ... why are the relays/contactors arcing closed as per sunsynk video SA visit ? 

Maybe one of the engineers can educate us on these additional protection features ? 

 

 

5 hours ago, isetech said:

Arc protection ... why are the relays/contactors arcing closed as per sunsynk video SA visit ?

Because South African's are a special breed, and think nothing of stress testing everything way passed all limits. 😂😂

The inverter is an 8.8 kW machine, but can safely pass through 12 kW of power, but in this part of the world we expect it to pass through even more like maybe 19 kW, and then wonder why components are damaged!!  🤔

This is not an inverter problem, but an installation / user problem.

This is equivalent to "chipping" your car and removing the rev limiter and crying when you blow your engine as you hit 20 000 RPM. 🤣

 

On the relay contact welding: So, looking at the Sunsync installer manual, there is no reference to what size MCB has to be installed. The specification says maximum continuous AC passthrough: 90A. Given that domestic installations should have a main MCB of max 80A, I think that the problem is not with the installation, but rather the relay. An 80A C-curve MCB can pass through 5-10 times its rated current. (C-curves are commonly used here.) The Relay can not handle that. An induction motor can draw 3-5 times its rated current for more than 1 second on startup (they are usually the contact killers). I am guessing that the MCB to/from the inverter should be B-curve and probably be rated a lot lower than the relays max current.

Anyway, I have heard of relay failures on Sunsynk, and not on other brands (well maybe a couple, but I'd rather not mention them). Point is - there are inverters that I have not heard of a relay failure*. Perhaps Sunsynk should look at the relays that don't fail and start testing.

 

* That is not to say that there aren't any, and keep in mind that significant bias in the statistics exist based on the number of a specific inverter being used. For instance if there are 1000 Sunsynks and 10 relays have failed; compared to 100 PremiumBrand™ inverters that have 5 with failed relays, it would seem like the SunSynks have double the failures if you are not aware of the 1000/100 totals. In real terms one has 1% failures and the other 5%.

 

Edited November 15, 20214 yr by P1000

Circuit breakers are not designed to protect the equipment (the inverter should have built in protection to prevent overloading ... prevent the relay/contactor from arcing closed ... circuit breakers are used to design the electrical wiring configuration ... ie if you installing a 5 kva unit ... lets go big and say 25 - 30 maps max ... in theory the wire should be sized at 4 mm ... I have noticed some go 6 mm (we not talking earthing for now)  ... which is even a little over kill for a 20 amp unit ... but hey we like to be safer ... installing 16 mm wire with a 60 amp breaker ... eeeiish ... there goes your quote out the window. 

For example ... If I install a 7.5 kw motor for a pump ... I dont fit a 60 amp breaker and use 16 mm wire ... just because the motor has a significantly higher start up current ... the motor will have overload protecting in the Starter ... I use a 2.5 mm wire with a 20 amp breaker ... lets not complicate things and just say it is close to the DB ... so we not going to take volt drop and distance and those things into considerations ( we generally talking domestic installations on this platform)

I would think just like a motor ... the inverter should have some form of protection ... like the axpert I think it has a 40 amp protective device ... I have heard that the oversized protection has to do with the different voltages 110 - 230 ... the 5000/110= 45 amps and 5000/240=21.7 amps ... this is just hear say ... it makes sense but that what I have heard is the reason.

I am assuming that the importer has no SANS certification for the unit . ... hence they can get away with unloading the units without fitting the correct protection ??? 

You should be asking this question if your warranty claim is rejected ... did the units  protection device fail or was it the installers who was negligent for not checking the unit had the correct protection or documentation and certification prior to installing the unit at the time of completing the COC for he installation ? 

Edited November 15, 20214 yr by isetech

Then we complicate things and start connecting units in parallel.